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EP-4737928-A1 - METHOD AND APPARATUS FOR DETECTING INSULATION DEFECT OF BATTERY, AND BATTERY SYSTEM

EP4737928A1EP 4737928 A1EP4737928 A1EP 4737928A1EP-4737928-A1

Abstract

A method for detecting an insulation defect in a battery may be provided. The method for detecting insulation defect includes measuring a first voltage corresponding to a voltage of a positive terminal of a battery rackduring a first duration; measuring a second voltage corresponding to a voltage of the positive terminal of the battery rack and a third voltage corresponding to a voltage of a negative terminal of the battery rack, respectively, during a second duration; measuring a fourth voltage corresponding to a voltage of the negative terminal of the battery rack during a third duration; measuring an insulation resistance value of the battery rack based on the first voltage and the fourth voltage; and determining whether the battery rack has the insulation defect based on the insulation resistance value of the battery rack.

Inventors

  • OKUI, YOSHIAKI

Assignees

  • SAMSUNG SDI CO., LTD.

Dates

Publication Date
20260506
Application Date
20251010

Claims (15)

  1. A method for detecting an insulation defect in a battery comprising: measuring a first voltage corresponding to a voltage of a positive terminal of a battery rack (110) during a first duration (D1); measuring a second voltage corresponding to the voltage of the positive terminal of the battery rack (110) and a third voltage corresponding to a voltage of a negative terminal of the battery rack (110), respectively, during a second duration (D2); measuring a fourth voltage corresponding to the voltage of the negative terminal of the battery rack (110) during a third duration (D3); measuring an insulation resistance value of the battery rack (110) based on the first voltage and the fourth voltage; and determining whether the battery rack (110) has the insulation defect based on the insulation resistance value of the battery rack (110).
  2. The method as claimed in claim 1, further comprising: detecting a position of the insulation defect in the battery rack (110) using the second voltage and the third voltage if the battery rack (110) is determined to have defective insulation.
  3. The method as claimed in claim 2, wherein the detecting a position of the insulation defect comprises: calculating a ground fault voltage using the second voltage, the third voltage, and the insulation resistance value; calculating a voltage between the positive terminal of the battery rack (110) and ground using the ground fault voltage and the second voltage; calculating a relative position of the insulation defect using the ground fault voltage and the voltage between the positive terminal of the battery rack (110) and ground; and specifying the position of the insulation defect from the relative position of the insulation defect.
  4. The method as claimed in claim 3, wherein the relative position of the insulation defect indicates a ratio of a distance between the negative terminal of the battery rack (110) and the positive terminal of the battery rack (110) and a distance from a position of the negative terminal of the battery rack (110) to the position of the insulation defect, as a percentage (%).
  5. The method as claimed in claim 4, wherein the specifying a position of the insulation defect comprises: if the relative position of the insulation defect is 0%, specifying the position of the negative terminal of the battery rack (110) as the position of the insulation defect; if the relative position of the insulation defect is 100%, specifying the position of the positive terminal of the battery rack (110) as the position of the insulation defect; and if the relative position of the insulation defect is 50%, specifying a middle position between the negative terminal of the battery rack (110) and the positive terminal of the battery rack (110) as the position of the insulation defect.
  6. The method as claimed in any one of the preceding claims, wherein: the measuring the first voltage during the first duration comprises turning on a first switch (310) connected between the positive terminal of the battery rack (110) and an inverting input terminal of a first operational amplifier (512, 522), the measuring the fourth voltage during the third duration comprises turning on a second switch (320) connected between the negative terminal of the battery rack (110) and an inverting input terminal of a second operational amplifier (512, 522), and measuring the second voltage and the third voltage during the second duration comprises turning on the first switch (310) and the second switch (320) simultaneously.
  7. An insulation defect detection apparatus (500) comprising: a first voltage meter (510) configured to measure a voltage of a positive terminal of a battery rack (110); a second voltage meter (520) configured to measure a voltage of a negative terminal of the battery rack (110); a controller (540) configured to measure the voltage of the positive terminal as a first voltage during a first duration, measure the voltage of the positive terminal and the voltage of the negative terminal as a second voltage and a third voltage respectively during a second duration, and measure the voltage of the negative terminal as a fourth voltage during a third duration; and an insulation resistance meter (530) configured to detect an insulation status of the battery rack (110) using the first voltage, the second voltage, the third voltage, and the fourth voltage.
  8. The insulation defect detection apparatus (500) as claimed in claim 7, wherein the insulation resistance meter (530) is configured to measure an insulation resistance value of the battery rack (110) based on the first voltage and the fourth voltage, and determine that an insulation of the battery rack (110) is defective if the insulation resistance value of the battery rack (110) is lower than or equal to a set threshold value.
  9. The insulation defect detection apparatus (500) as claimed in claim 8, wherein the insulation resistance meter (530) is configured to detect a position of an insulation defect in the battery rack (110) using the second voltage and the third voltage if the battery rack (110) is determined to have defective insulation based on the insulation resistance value of the battery rack (110).
  10. The insulation defect detection apparatus (500) as claimed in claim 9, wherein the insulation resistance meter (530) is configured to calculate a ground fault voltage using the second voltage, the third voltage, and the insulation resistance value, calculate a voltage between the positive terminal of the battery rack (110) and ground using the ground fault voltage and the second voltage, calculate a relative position of the insulation defect using the ground fault voltage and the voltage between the positive terminal of the battery rack (110) and ground, and specify the position of the insulation defect from the relative position of the insulation defect.
  11. The insulation defect detection apparatus (500) as claimed in claim 10, wherein the relative position of the insulation defect indicates a ratio of a distance between the negative terminal of the battery rack (110) and the positive terminal of the battery rack (110) and a distance from a position of the negative terminal of the battery rack (110) to the position of the insulation defect, as a percentage (%).
  12. The insulation defect detection apparatus (500) as claimed in claim 11, wherein the insulation resistance meter (530) is configured specify the position of the negative terminal of the battery rack (110) as the position of the insulation defect if the relative position of the insulation defect is 0%, specify the position of the positive terminal of the battery rack (110) as the position of the insulation defect if the relative position of the insulation defect is 100%, and specify a middle position between the negative terminal of the battery rack (110) and the positive terminal of the battery rack (110) as the position of the insulation defect if the relative position of the insulation defect is 50%.
  13. The insulation defect detection apparatus (500) as claimed in claim 10, wherein: the first voltage meter (510) is configured to comprise a first operational amplifier (512, 522) and a first switch (310) connected between a first input terminal of the first operational amplifier (512, 522) and the positive terminal of the battery rack (110), the second voltage meter (520) is configured to comprise a second operational amplifier (512, 522) and a second switch (320) connected between a second input terminal of the second operational amplifier (512, 522) and the negative terminal of the battery rack (110), and the controller (540) is configured to turn on only the first switch (310) during the first duration, maintain an on state of the first switch (310) and turn on the second switch (320) during the second duration, and turn off the first switch (310) and maintain an on state of the second switch (320) during the third duration.
  14. A battery system (100) comprising: a battery rack (110) configured to comprise a plurality of battery cells; and a rack battery management system, RBMS, (120) configured to measure a voltage of a positive terminal as a first voltage during a first duration, measure the voltage of the positive terminal and a voltage of a negative terminal as a second voltage and a third voltage respectively during a second duration after the first duration, measure the voltage of the negative terminal as a fourth voltage during a third duration after the second duration, and detect an insulation status of the battery rack (110) using the first voltage, the second voltage, the third voltage, and the fourth voltage.
  15. The battery system (100) as claimed in claim 14, wherein the rack battery management system (120) is configured to measure an insulation resistance value of the battery rack (110) based on the first voltage and the fourth voltage, and determine that an insulation of the battery rack (110) is defective if the insulation resistance value of the battery rack (110) is lower than or equal to a set threshold value.

Description

FIELD This disclosure relates to a method and apparatus for detecting insulation defect in a battery, and a battery system. BACKGROUND An energy storage system (ESS) may include a plurality of battery cells. If an insulation defect in even one of the plurality of battery cells occurs, it may lead to a fire. Therefore, it is important to monitor the insulation status of the battery cells. The most widely used insulation monitoring method today is the method of using an insulation monitoring device (IMD), which may monitor the insulation status through changes in the insulation resistance if insulation breakdown or insulation deterioration occurs. Therefore, it is difficult to accurately find the position of insulation defect in ESS where the plurality of battery cells are connected in series and/or parallel. SUMMARY The invention is defined by the appended claims. The description that follows is subjected to this limitation. Any disclosure lying outside the scope of said claims is only intended for illustrative as well as comparative purposes. At least embodiments provide a method and apparatus for detecting an insulation defect in a battery, and a battery system, capable of specifying a position of the insulation defect. According to an aspect of the present invention, a method for detecting an insulation defect is provided. The method for detecting the insulation defect includes: measuring a first voltage corresponding to a voltage of a positive terminal of a battery rack during a first duration; measuring a second voltage corresponding to a voltage of the positive terminal of the battery rack and a third voltage corresponding to a voltage of a negative terminal of the battery rack, respectively, during a second duration; measuring a fourth voltage corresponding to the voltage of the negative terminal of the battery rack during a third duration; measuring an insulation resistance value of the battery rack based on the first voltage and the fourth voltage; and determining whether the battery rack has the insulation defect based on the insulation resistance value of the battery rack. The method for detecting insulation defect may further include detecting a position of the insulation defect in the battery rack using the second voltage and the third voltage if the battery rack is determined to have defective insulation. The detecting the position of the insulation defect may include: calculating a ground fault voltage using the second voltage, the third voltage, and the insulation resistance value; calculating a voltage between the positive terminal of the battery rack and ground using the ground fault voltage and the second voltage; calculating the relative position of the insulation defect using the ground fault voltage and the voltage between the positive terminal of the battery rack and ground; and specifying a position of the insulation defect from the relative position of the insulation defect. The relative position of the insulation defect may indicate a ratio of a distance between the negative terminal of the battery rack and the positive terminal of the battery rack and a distance from a position of the negative terminal of the battery rack to the position of the insulation defect, as a percentage (%). The specifying a position of the insulation defect may include specifying the position of the negative terminal of the battery rack as the position of the insulation defect if the relative position of the insulation defect is 0%; specifying the position of the positive terminal of the battery rack as the position of the insulation defect if the relative position of the insulation defect is 100%; and specifying a middle position between the negative terminal of the battery rack and the positive terminal of the battery rack as the position of the insulation defect if the relative position of the insulation defect is 50%. The measuring the first voltage during the first duration may include turning on a first switch connected between the positive terminal of the battery rack and an inverting input terminal of a first operational amplifier, the measuring the fourth voltage during the third duration may include turning on a second switch connected between the negative terminal of the battery rack and an inverting input terminal of a second operational amplifier, and measuring the second voltage and the third voltage during the second duration may include turning on the first switch and the second switch simultaneously. According to another aspect of the present invention, an insulation defect detection apparatus is provided. The insulation defect detection apparatus includes: a first voltage meter configured to measure a voltage of a positive terminal of a battery rack; a second voltage meter configured to measure a voltage of a negative terminal of the battery rack; a controller configured to measure the voltage of the positive terminal as a first voltage during a first duration, measure the voltage of the